I'm sorry if this has been addressed before...
While the typical GJ pick is thick, and strong(ish), the picks I've seen from Wegen, AK, Moustache, etc. all tend to be very lite-weight. Literally. I would think that playing a heavier pick would also affect the tone that you acheived. Has anyone experimented with playing picks of similar shapes and thicknesses, but with differing weights?
Reject the null hypothesis.